Water preparation device, in particular for a drain cleaning vehicle

ABSTRACT

The invention relates to a water preparation device ( 1 ), in particular for a drain cleaning vehicle. Said device comprises a separation device ( 2 ) for a supplied mud-water mixture and a water tank ( 8 ) for clean water that is connected to said device. The separation device ( 2 ) and the water tank ( 8 ) form a structural unit and the water tank ( 8 ) for clean water at least partially surrounds the separation device ( 2 ) for the mud-water mixture.

The invention relates to a water treatment means, especially for use inconjunction with a sewer cleaning vehicle, as claimed in the preamble ofclaim 1.

Municipal vehicles, especially sewer cleaning vehicles, are used mainlyto clean sewers and the like. They are also used to clear sewer clogs,for street cleaning after heavy precipitation with trash accumulation,floods, for sucking dirt and mud out of containers and tanks, and soforth. They comprise a tank which is mounted on the chassis of a truckand which is divided into several chambers. The generally cylindricallymade, barrel-like tank is conventionally arranged horizontally. In oneversion of these sewer cleaning vehicles known from the prior art, thetank viewed from the back end of the vehicle has a first larger chamber,in which stones, gravel and mud settle out of the mud-water mixturewhich has been picked up by a suction hose. The mud chamber in thedirection of the cab has a separation chamber in which the mud-watermixture which has been entrained with suction air is separated from thelatter and the water is separated from the mud. Toward the cab a freshwater tank follows; it is used to store fresh water which is used toclean sewers, tanks and barrels which have been cleaned beforehand witha high pressure water jet. There is a separate high pressure pump forproducing the pressure which is necessary for this purpose. The negativepressure which is necessary for sucking up the water-mud mixture isproduced by a vacuum pump, for example a water ring pump, which islocated within the fresh water chamber in the known embodiment.

The fresh water chamber and the separator occupy a large part of thetank volume. This volume is lacking in the mud chamber for holding thesuctioned mud. For this reason the mud chamber reaches the maximum filllevel more quickly and the cleaning process must be interrupted to emptyit. Moreover, the mud chamber which can assume a relatively great weightin operation is located very far to the back on the vehicle. Inconjunction with the boom located on the back end of the tank for themud suction hose and the reel mounted on the end of the tank for thehigh pressure hose, a very unfavorable weight distribution of the sewercleaning vehicle results. This can lead to excess wear on the rearwheels of the vehicle. The unfavorable center of gravity can even leadto the steerability of the vehicle being adversely affected.

To remedy this situation, in another known sewer cleaning vehicle it hasbeen proposed that the water treatment means which comprises theseparator and fresh water tank be moved out of the horizontalcylindrical tank. In this arrangement, between the cab and the tankabove the vehicle frame, a space is left open and holds the fresh watertank, the separator, for example a cyclone, and the vacuum pump,generally a water ring pump. The water ring pump is located between theseparator and the fresh water tank which are mounted on the right andleft on the vehicle frame. This arrangement makes it possible to makethe mud tank longer. The increase in the volume provides for longer,uninterrupted operation and also improves the weight distribution on thevehicle. The disadvantage in this arrangement is that the width of thevehicle is relatively great due to the lateral arrangement of theseparator and the fresh water tank. This can lead to adverse effects inuse of the sewer cleaning vehicle under the narrow conditions ofEuropean municipalities.

The object of this invention is to avoid the disadvantages of the sewercleaning vehicle of the prior art. A water treatment means will bedevised which can be mounted in a space-saving manner especially on asewer cleaning vehicle. The water treatment means is designed to make itpossible to equip a sewer cleaning vehicle with a mud tank having arelatively large volume, and to enable a favorable weight distributionand arrangement of the center of gravity. The water treatment means isto be made as compact as possible so that when mounted on a sewercleaning vehicle, the width of the vehicle can be kept as small aspossible and even under narrower road conditions full utility of thevehicle is ensured.

To achieve these objects, the invention proposes a water treatment meansespecially for a sewer cleaning vehicle, which has the features cited inthe characterizing section of claim 1. Developments and/or advantageousversions of the invention are the subject matter of the dependentclaims.

The invention devises a water treatment means, especially for a sewercleaning vehicle, which comprises a separation device for a suppliedair-mud-water mixture and a water tank which is connected to it forcleaned water. The separation device and the water tank form astructural unit. The separation device for the air-mud-water mixture issurrounded at least in areas by the water tank for the cleaned water.

The separation device for the water-mud mixture and the water tank forthe cleaned water are combined by the design measure as claimed in theinvention into a structural unit and can be transported, manipulated andmounted integrally. The water treatment means is made compact andspace-saving by the water tank's at least partially surrounding theseparation device for the mud-water mixture. Especially for installationon the sewer cleaning vehicle this enables a space-saving arrangement ofthe water treatment means and better weight distribution of the vehicle.The space gained can be used for example for a larger mud tank.

In one especially space-saving design of the water treatment means, theseparation device and the water tank are arranged essentiallyconcentrically. The water tank for example has an essentiallycylindrical shape. The separation device is then conventionally alsomade cylindrical. The arrangement is then essentially coaxial.

The separation device for the mud-water mixture is made as a mudseparator with a reservoir for the separated mud. The separation deviceexploits the force of gravity. The mud-water mixture is delivered intothe separation device via a pipe at the point which is lowest in itsposition of use and is routed against for example a screen-like baffleplate. The mud settles on the base of the separation device in the mudreservoir. The cleaned air flows on to an outlet opening. The air flowis routed to the water ring pump in connection with the latter.

So that the water treatment means can be made as compact as possible, itis advantageous to make the separation device as slender as possible.Due to the flow distance which is necessary for reliable separation ofthe mud-water mixture, the separation device conventionally has a largeroverall height than the water tank. So that the compact designed ispreserved, the separation device which is located vertically in itsposition of use penetrates the water tank in the axial direction.

One section of the water tank of the water treatment means isadvantageously made as a water separator. For example, the waterseparator is made as a cyclone. The air which has been compressed by thewater ring pump is conventionally mixed with water drops from the waterring pump. To recover the water, the compressed air is routed by way ofthe inflow opening in the water tank into the water separator. It isadvantageously made as a cyclone. The air mixed with the water drops isordinarily routed roughly tangentially into the cyclone. There the waterdrops which have been entrained with the air are separated into thewater tank. The air from which the water drops have been removed isblown into the open.

To recycle the water, the water tank is provided with at least oneoutlet by way of which water can be withdrawn for example from a waterring pump.

The water treatment means is made as a structural unit. So that it canbe combined easily with existing hardware components, for example asewer cleaning vehicle, the water tank surrounding the separation deviceis equipped with feed and drain connections for the intaken air. Thismakes it possible to easily connect the water treatment means to thevacuum means, for example a water ring pump. In this way theprerequisites are created for making the water treatment meansindependent of the configuration of the mud tank. The water treatmentmeans as claimed in the invention can also be mounted for example onexisting sewer cleaning vehicles in place of the separate separationdevice and the separate water tank since all necessary connections arealready integrated. A manufacturer of sewer cleaning vehicles can thusprocure the water treatment means independently of the vehiclecomponents; this increases his economic flexibility.

For operation of the water treatment means, especially on a sewercleaning vehicle, it is advantageous if it is already equipped with anintegrated switching means for the air flows into and out of theseparation device and the water tank. The switching means, generally afour-way switch, is matched to the requirements of the water treatmentmeans and need only be connected to a power supply source, for exampleto the electrical system of the sewer cleaning vehicle.

A sewer cleaning vehicle equipped with a water treatment means made asclaimed in the invention has more space due to the compact dimensions ofthe water treatment means. This space can be used for example toincrease the volume of the mud tank. The compact execution of the watertreatment means allows installation in a vertical state next to therequired vacuum pump, for example a water ring pump, between the cab anda horizontally arranged mud tank. The vacuum pump, in many cases a waterring pump, takes water directly from the water tank which is locatednext to it. The negative pressure which is produced is used to intakeboth the mud-water mixture and the cleaned water, but also to supportseparation of the mud water-mixture in the cyclone. The suctiondistances can be kept small by the advantageous arrangement of the waterring pump and the water treatment means. This has advantages for theattainable vacuum performance. The space which has been gained by thespace-saving arrangement can be used to move the mud tank farther in thedirection of the cab. This improves the weight distribution and thelocation of the center of gravity of the sewer cleaning vehicle. It canthus also be more easily and safely maneuvered.

The prior art discloses sewer cleaning vehicles in which the mud tank istipped to empty it. Because of the complete separation of the watertreatment means from the mud tank, only the mud tank need be tipped. Thewater treatment means maintains its position on the vehicle unchangedwhen the mud tank is tipped. This simplifies construction. The mass tobe tipped is reduced by the mud tank alone having to the tipped to emptyit; this entails advantages with respect to the fuel consumption of thesewer cleaning vehicle.

Other advantages and features of the invention follow from thedescription of one embodiment of the invention below and its use in asewer cleaning vehicle. The schematics are not to scale.

FIG. 1 shows a water treatment means as claimed in the invention ininteraction with a vacuum means, for example a water ring pump, and amud tank; and

FIG. 2 shows the arrangement of a water treatment means as claimed inthe invention on a sewer cleaning vehicle.

FIG. 1 shows a water treatment means as claimed in the invention whichbears reference number 1 overall, in interaction with a mud tank 20 andwith a vacuum pump 30, especially with a water ring pump. When sewersare being suctioned, rocks, gravel and mud are collected in the mud tank20. The air which is suctioned by way of the intake opening 22 of themud tank 20, which opening is provided with a valve 25, always entrainsa mud-water mixture which must be separated in the water treatment means1 before the air is delivered again to the vacuum pump 30.

The water treatment means 1 comprises a separation device 2 for asuctioned mud-water mixture which is located essentially concentricallyor coaxially to the water tank 8 for the cleaned water. The separationdevice 2 and the water tank 8 have an essentially cylindrical shape andare arranged vertically in the position of use of the water treatmentmeans 1.

The separation device 2 at its lowest point has an inlet 3 for themud-water mixture which has been entrained with the intaken air. Thecylindrical inlet connection 3 ends in front of the baffle plate 4. Theentrained mud-water mixture sprays against the baffle plate and settleson the bottom of the separation device 2 in a mud reservoir 5. The airflows on by way of the outlet opening 6 of the separation device and anoutlet 17 in the direction of the vacuum pump 30 which is made as awater ring pump. The air generally picks up water drops in the waterring pump 30. Ordinarily the now compressed air which is mixed withwater drops travels by way of the inflow opening 9 in the water tank 8somewhat tangentially into a section of the water tank 8 which is madeadvantageously as a cyclone 18. There the water drops which have beenentrained with the air are separated into the water tank 8. The air fromwhich the water drops have been removed travels by way of an outflowopening 10 of the water tank 8 which is connected to the outflow opening7 of the separation device 2, and an outlet 16 into the open.

There are an outlet 16 to the open and an outlet 17 in the direction ofthe water ring pump on a switching device which is labelled withreference number 15. The switching device 15 is made as a four-way valveand provides for control of the air flows out of the separation device 2and out of the water tank 8. Advantageously the switching device isconnected to the water treatment means 1 to form a structural unit whichcan be handled jointly. The inlets of the switching device 15 coincidewith the outflow openings 6, 7 of the separation device 2. The switchingdevice 15 provides for routing the air flows via the outlets 6 and 7 ofthe separation device 2.

The right half of the symbolically shown switching device 15 indicates asecond operating state and the pertinent flow directions by thecorresponding arrows. In this case which is necessary for example toempty the water treatment means 1 and also the mud tank 20, the airflows are reversed. The water ring pump 30 intakes air via the outlets16, 17 from the vicinity. The compressed air which optionally entrainswater drops from the water ring pump 30 is routed via openings 9, 10, 7and 6 into the water tank 8 and the separation device 2. From there ittravels via the inlet 3 of the separation device 2 and the suctionopening 22, 25 into the mud tank 20 as well.

The water treatment means 1 is connected via the switching device to oneinlet 31 of the water ring pump 30. Water ring pumps have been longknown from the prior art, and one consists of a cylindrical housing inwhich an impeller with radial, straight or curved blades is located. Theshaft of the impeller is supported eccentrically to the surroundinghousing. The housing is partially filled with water via a line. In theillustrated embodiment the water ring pump is supplied with water via aline which connects the outlet 11 in the water tank 8 to the inlet 33 inthe housing of the water ring pump 30. When the impeller rotates, awater ring is formed in the housing and the blades dip more or lessdeeply into the ring due to the eccentric support of the shaft. Theindividual cells which are divided by the blades of the impeller in thewater ring periodically become larger or smaller during rotation.Suction and pressure openings are mounted in the side covers of thehousing such that the suction openings are located in the area of theenlarging cells, the pressure openings in the area of the diminishingcells. The air which has been intaken through the inlet opening 31 isintaken by the enlargement of the cell volumes, is compressed when thecell volumes become smaller, and is pressed out of the water ring pumpthrough the pressure opening 32. In any case, the water entrained withthe compressed air travels via the inlet 9 in the water tank into thearea of the cyclone 18, is separated from the air there, and settles inthe water tank 8. There it is ready again for supplying the water ringpump 30 with water. The air is released into the vicinity via theswitching device 15.

The mud tank 20 which is conventionally arranged horizontally has acover 21 which can be swivelled up and through which the dirt, rocks,gravel and mud which have settled in the tank can be emptied. In thecover area there is also a drain line 23 with a stop valve 24 via whichliquid components can be drained before emptying the mud tank.

FIG. 2 shows the arrangement of the water treatment means 1 as claimedin the invention on a sewer cleaning vehicle which is labelled withreference number 40 overall. The water treatment means 1 with aseparation device 2 which is surrounded by the water tank 8 follows thecab 41 which is located over the front axle, next to the vacuum pump 30on the frame 44 of the vehicle 40. A high pressure pump which is used togenerate the high pressure for the water jet for sewer cleaning islabelled with reference number 35. It is supplied for example from thewater tank 8 for the cleaned water. Therefore it is advantageous if thehigh pressure pump is likewise located in the vicinity of the watertreatment means 1. In FIG. 2 it is mounted on the vehicle frame 44. Inone alternative version it can however also be located underneath theframe for reasons of space. In this case it can also be moved farther inthe direction of the cab 41. The mud tank is labelled 20; it is movedfarther in the direction of the cab 41 due to the space-saving executionand arrangement of the water treatment means 1. In this way the mainload of the mud tank 20 is moved in front of or over the rear axles ofthe sewer cleaning vehicle 40 which are labelled with reference number43. The improved weight distribution has advantages with respect to themaneuverability of the vehicle and also leads to more uniform tire wear.The mud tank 20 can be made with a greater volume by virtue of thecompact execution of the water treatment means 1. In this way theintervals in which the mud tank must be emptied are made longer and theeffective service life of the sewer cleaning vehicle is prolonged.

1. Water treatment means, especially for a sewer cleaning vehicle,comprising a separation device (2) for a mud-water mixture which hasbeen supplied with intaken air and a water tank (8) which is connectedto it for cleaned water, characterized in that the separation device (2)and the water tank (8) form a structural unit and the separation device(2) for the air-mud-water mixture is surrounded at least in areas by thewater tank (8) for the cleaned water.
 2. Water treatment means asclaimed in claim 1, wherein the separation device (2) and the water tank(8) are arranged essentially concentrically.
 3. Water treatment means asclaimed in claim 1 or 2, wherein the separation device (2) comprises amud separator with a reservoir (5) for the settled mud.
 4. Watertreatment means as claimed in one of the preceding claims, wherein theseparation device (2) axially penetrates the water tank (8).
 5. Watertreatment means as claimed in claim 4, wherein the separation device (2)at its point which is the lowest in the position of use has one inlet(3) for an air-mud-water mixture which is to be separated and on itsopposite end there is an outlet (7) for cleaned air.
 6. Water treatmentmeans as claimed in one of the preceding claims, wherein one section(18) of the water tank (8) is made as a water separator for water whichis entrained with the air.
 7. Water treatment means as claimed in claim6, wherein the water separator (18) is a cyclone.
 8. Water treatmentmeans as claimed in one of the preceding claims, wherein the water tank(8) is provided with at least one outlet (11) by way of which forexample a vacuum device, especially a water ring pump (30), can besupplied with water.
 9. Water treatment means as claimed in one of thepreceding claims, wherein it is equipped with an integrated switchingmeans (15) for the air flows into and out of the separation device (2)or the water tank (8).
 10. Water treatment means as claimed in claim 9,wherein the switching means (15) is a four-way valve.
 11. Sewer cleaningvehicle with a water treatment means (1) as claimed in one of thepreceding claims.
 12. Sewer cleaning vehicle as claimed in claim 11,wherein the water treatment means (1) is located in the vertical statenext to a vacuum pump, for example a water ring pump (30), between thecab (41) and a horizontally arranged mud tank (20).
 13. Sewer cleaningvehicle as claimed in claim 12, wherein the water treatment means (1)maintains its position unchanged on the vehicle (40) when the sludgetank (2) with a tipping capacity is tipped.